For irradiating a layer (3) a radiation beam (7) is directed and focused to a spot (11) on the layer (3), relative movement of the layer (3) relative to the optical element (59) is caused so that, successively, different portions of the layer (3) are irradiated and an interspace (53) between a surface of the optical element (59) nearest to the layer (3) is maintained. Furthermore, at least a portion of the interspace (53) through which the radiation irradiates the spot (11) on the layer (3) is maintained filled with a liquid (91). By directing a gas flow (71-73) to a surface zone (74) of the layer (3), liquid (91) is reliably prevented from passing that surface zone (74), without causing damage to the layer (3). The liquid (91) is drawn away from the layer (3) in the vicinity of the surface zone (74).
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of irradiating a layer ( 3 ) including: directing and focusing a radiation beam ( 7 ) to a spot ( 11 ) on said layer ( 3 ) by means of at least one optical element ( 59 ); causing relative movement of the layer ( 3 ) relative to said at least one optical element ( 59 ) so that, successively, different portions of the layer ( 3 ) are irradiated and an interspace ( 53 ) between a surface of said at least one optical element ( 59 ) nearest to said layer ( 3 ) is maintained; and maintaining at least a portion of said interspace ( 53 ) through which said radiation irradiates said spot ( 11 ) on said layer ( 3 ) filled with a liquid ( 91 ) supplied via a supply conduit; characterized by directing gas ( 71 - 73 ) to said layer ( 3 ); and removing supplied liquid ( 91 ) from said layer ( 3 ) in the vicinity of a flow of said gas ( 71 - 73 ).
2. A method according to claim 1 , wherein said gas ( 71 - 73 ) is supplied at a pressure sufficiently high to cause a net gas flow ( 71 - 73 ) in a direction along said layer ( 3 ) opposite to the direction ( 30 ) of said movement of said layer ( 3 ).
3. A method according to claim 1 or 2 , wherein the flow of said gas ( 71 - 73 ) is entered into an interspace between said layer ( 3 ) and a boundary surface ( 83 ) having a width of at least 2 μm and preferably at least 5 μm and at most 100 μm and preferably 30 μm.
4. A method according to claim 3 , wherein the liquid ( 91 ) forms a film on said layer ( 3 ) having a thickness, and wherein an interspace ( 86 ) between said layer ( 3 ) and a surface ( 87 ) facing said layer ( 3 ) upstream of an area where the liquid is discharged is larger than the thickness of said film.
5. A method according to any one of the preceding claims, wherein liquid ( 91 ) and gas are drawn away from said layer ( 3 ) at a higher flow rate than the sum of the flow rates of said gas flow ( 71 - 73 ) and the supply of said liquid ( 91 ).
6. A method according to any one of the preceding claims, wherein said gas ( 71 - 73 ) is air.
7. A device for directing radiation to a layer ( 3 ) including: at least one optical element ( 59 ) for focusing a beam ( 7 ) of radiation originating from a radiation source ( 33 ) to a spot ( 11 ) on said layer ( 3 ); a displacement structure for causing relative movement of the layer ( 3 ) relative to said at least one optical element ( 59 ) so that, successively, different portions of the layer ( 3 ) are irradiated and an interspace ( 53 ) between said layer ( 3 ) and a surface of said at least one optical element ( 59 ) nearest to said spot ( 11 ) is maintained; and an outflow opening for supplying liquid ( 91 ) to at least a portion of said interspace ( 53 ) through which, in operation, said radiation irradiates said spot ( 11 ) on said layer ( 3 ); characterized by a gas outflow opening ( 70 ) for directing a gas flow ( 71 - 73 ) to said layer ( 3 ); and a discharge channel ( 76 ) having an inlet ( 77 ) in the vicinity of said gas outflow opening ( 70 ) for drawing away liquid ( 91 ) from the layer ( 3 ).
8. A device according to claim 7 , wherein said gas outflow opening ( 70 ) for directing said gas flow ( 71 - 73 ) is a slit.
9. A device according to claim 7 or 8 , wherein said discharge channel ( 76 ) communicates with a vacuum source ( 81 ).
10. A device according to any one of the claims 7 - 9 , wherein said gas outflow opening ( 70 ) and said inlet ( 77 ) of said discharge-channel ( 76 ) extend about said interspace ( 53 ).
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
November 14, 2003
April 15, 2008
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